Threatened Sustainability: the Uncertain Future of Thailand’s Solar Home Systems Andrew Lynch, Chris Greacen, Salinee Tavaranan, Fredrik Bjarnegard Border Green Energy Team June 2006 Introduction First announced in 2003, Thailand is approaching completion of an ambitious program initiated by acting Prime Minister Thaksin Shinawatra for the installation of approximately 200,000 solar home systems (SHS). 1 The Thai Solar Home System program (known in Thai language as the “Krong Gan Fai Fa Euah Athorn” or “Electricity Handout Program”) adds about 22.7 MW of solar electricity to the total installed solar capacity in Thailand, which stood at just 6 MW in 2003. The program brings Thailand’s rural electrification rate 2 to nearly 100%, and provides valuable electricity to Thai villages that do not have access to grid electricity. While it appears that the installations were quickly -- and in most cases, professionally -- done, considerable questions remain concerning the sustainability of these solar electric systems in light of several factors: virtually no local knowledge on solar home system repair, lack of locally available replacement parts, and lack of information on the part of system users concerning the existence of the system’s warranty. This study discusses results from a survey of the status of 405 Thai solar home systems in two districts in Tak province. The survey finds that out of the 405 systems, 22.5% were broken within the first year. Most of the equipment failures 1 Hirshman, W. P. and D. Ruppik (2006). "Thai-ing up the votes?" Photon International: April. 62-64. 2 “electrification rate” refers to the percentage of villages electrified, not households electrified.
Transcript
Threatened Sustainability: the Uncertain Future of Thailand’s Solar Home Systems
Andrew Lynch, Chris Greacen, Salinee Tavaranan, Fredrik BjarnegardBorder Green Energy Team
June 2006
IntroductionFirst announced in 2003, Thailand is approaching completion of an ambitious program initiated by acting Prime Minister Thaksin Shinawatra for the installation of approximately 200,000 solar home systems (SHS).1 The Thai Solar Home System program (known in Thai language as the “Krong Gan Fai Fa Euah Athorn” or “Electricity Handout Program”) adds about 22.7 MW of solar electricity to the total installed solar capacity in Thailand, which stood at just 6 MW in 2003. The program brings Thailand’s rural electrification rate2 to nearly 100%, and provides valuable electricity to Thai villages that do not have access to grid electricity.
While it appears that the installations were quickly -- and in most cases, professionally -- done, considerable questions remain concerning the sustainability of these solar electric systems in light of several factors: virtually no local knowledge on solar home system repair, lack of locally available replacement parts, and lack of information on the part of system users concerning the existence of the system’s warranty. This study discusses results from a survey of the status of 405 Thai solar home systems in two districts in Tak province. The survey finds that out of the 405 systems, 22.5% were broken within the first year. Most of the equipment failures were faulty inverter/charge-controllers and fluorescent light ballasts. This study discusses the technical nature of these failures, and identifies important linkages among failures of different components.
Another key concern regarding the program is the ability of the project implementers to learn lessons from the field. The program appears to lack important linkages from the grassroots level back to decision-makers so that the existing program can be sustainable and future programs can improve. This paper discusses the administrative arrangements in the program, and describes efforts by one grass roots group to address information/knowledge gaps in the program.
Thai solar home system descriptionCompared to many solar home system designs, which have a single solar module of 35 to 75 watts peak, Thailand’s solar home systems are large. Each system comprises a 120 watt peak panel3, a 150 watt inverter/charge controller, a 125-Ah 12-volt battery, and two 10-watt fluorescent lights (Figure 1). This is sufficient to provide
1 Hirshman, W. P. and D. Ruppik (2006). "Thai-ing up the votes?" Photon International: April. 62-64.2 “electrification rate” refers to the percentage of villages electrified, not households electrified.3 About 75% of the solar modules are single crystalline silicon, and the remainder are amorphous silicon.
electricity for several hours of lighting (two 10-watt bulbs) and an hour or so of TV and/or VCD video per night. Total energy production from the solar panel is about 350 to 450 watt-hours/day. Maximum continuous power output is limited by the inverter’s capacity to about 150 watts.
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3KDEEP CY CLE
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Figure 1: Solar home systems comprise a 120 watt solar module, a 125-Ah 12-volt battery, and a combination inverter/charge controller. Maximum power output from the system is 150 watts. The system shown is the type installed by Solartron in Tak province.
Description of the Thai government SHS program With an initial target to provide electricity to the majority of Thailand’s 290,716 off-grid households, the installation of solar home systems was planned in two phases over a period of two years, starting April, 2003 and finishing April, 2005. The first phase initially provided for the installation of 153,000 SHS; this figure has been reduced to 138,996 systems, all of which are now installed, with the balance of systems being shifted to the second phase. The second phase, currently underway, is to install the 15,242 remaining first phase systems and 34,757 additional SHS with a total of just under 50,000 total systems to be installed. This will bring the total SHS from both phases to 188,995, somewhat lower than the goal of over 200,000 systems. The following tables4 show the geographic distribution of SHS in Thailand:
Phase 1 Phase 2Region Total SHS % of Phase Region Total SHS % of PhaseNorth 66,210 48.0 North 24,709 49.4Northeast 21,815 15.8 Northeast 20,232 40.5Central 17,619 12.8 Central 0 0.0
4 Data from the Bangkok office of the PEA
South 32,352 23.4 South 5,058 10.1Total 137,996 Total 49,999
Containing nearly half of all SHS installed, Northern Thailand has by far the most systems and more than twice as many as Northeast Thailand, the region with the next largest number of SHS. Southern Thailand, with just under twenty percent of Thai SHS, follows the Northeast in system distribution, and last comes Central Thailand, with under ten percent of all SHS. This distribution makes sense, as Northern Thailand is the most rural and isolated regions in Thailand with the lowest average population density (please see Appendix A for attached maps comparing Thai population density and SHS distribution). While Northeast Thailand has many provinces with high population density, it is also a very large region and includes more rural provinces with very low population density. It correspondingly has a large but not dominant percentage of SHS to provide electricity to its isolated households. Similarly, while Southern Thailand has areas of high population density, much of it is very rural and it has almost as many SHS as Northeast Thailand. Central Thailand, however, is both the most densely populated and perhaps more importantly is in close proximity to the technological and political nerve center of Thailand, Bangkok. Due to this, it contains under ten percent of Thailand’s SHS, most of these probably in the sparsely populated western provinces.
Bureaucratic arrangement and challenges with warrantyThe bureaucratic structure which supports the SHS starts with the taxpayer
funded Ministry of the Interior (MOI) which provided funds to the Provincial Electricity Authority (PEA), the government organization which is directly responsible for the SHS program. The PEA selected and contracted companies to install the solar home systems. Some of these companies also manufacture system components, which must be manufactured in Thailand according to PEA requirements.5
Solartron Public Company Limited 6 won bids for about three quarters of the solar panels, while Bangkok Solar Public Company Limited7 provided the remaining quarter. Inverters were manufactured by variety of Thai companies, including Forth8 and Power Solutions Technologies.9 Most of the batteries used in the system were manufactured by Thai Storage Battery Ltd. Public Company Limited (3K).10
All village households with a household registration (“tabien baan”) were eligible for solar home systems, free of charge. Initially, the solar home systems were 5 In the case of crystalline solar modules the cells are imported, but the modules are wired, sealed, and assembled in Thailand. 6 www.solartron.co.th7 www.bangkoksolar.com8 www.forth.co.th9 www.pst.co.th10 www.3kbattery.com/
Total (Both Phases)Region Total SHS % of PhaseNorth 90,919 48.4Northeast 42,047 22.4Central 17,619 9.4South 37,410 19.9Total 187,995
technically owned by the PEA, but currently details are being finalized to transfer ownership to the local sub-district (awbawtaw) government offices.
Ministry of Interior
PEA
Installation company
End users
$
$
SHS
warranty
Tax payers
$
Figure 2: Administrative arrangements in the Thai Solar Home Systems program.
The contracts also specify a warranty for the SHS, consisting of five years coverage for the solar panel modules, three years for the inverter/charge controller unit, and two years for the light/ballast systems and the batteries. To file a warranty claim a villager must contact the awbawtaw office. The awbawtaw then contacts the local PEA. It is the responsibility of the PEA to contact the company which installed the broken system; upon receipt of the claim information this company has seven business days in which to repair the system. For every day the repair work is late, a 200 baht fine per broken system is levied on the company responsible, the proceeds of which are paid to the PEA. It is not clear if this fine has ever been enforced.
The key problem with the warranty system is that villagers do not know it exists. In addition, there is no real support structure for filing the warranty claims. Indeed, there was no warranty form for the villagers to fill out if equipment breaks.
Despite the scale and expense of the SHS program, there has been very little provision established for its maintenance. The installation contract stipulates that the company must visit each system 18 months after installation to follow up and make repairs if necessary. It is not clear to what extent this follow-up work has been, or will be, done. As part of the official SHS programs there was little effort made to train locals in system operation and maintenance. Locals were warned “not to use too much electricity”, “not to use rice cookers and irons” to “not hang things on the solar panel or wires”. As discussed below, in the field, we have observed a number of system failures that result from operator error.
The lack of user training and local repair/maintenance capability is an especially glaring omission considering the relatively short warranty period, with a maximum of five years coverage, and user ignorance of how to take advantage of the warranty. As discussed in the section describing SHS survey data and analysis, systems are already starting to fail. When the warranty expires, there will be no
recourse for villagers with failed systems other than to pay for repairs and replacements themselves, something most cannot afford.
In addition to the lack of communication between villagers and awbawtaw government offices (and thus warranty providers), there is no system in place for villagers to provide feedback to other levels of the SHS program, namely the MOI and the PEA. Valuable user feedback which could lead to improved SHSs as well as perhaps a realization of the need for a maintenance program is thus made unavailable to the parties who could act on these issues. Just as important, the villagers have no way of providing feedback to the MOI and the PEA about the effectiveness of the installation companies.
Warranty awareness Self-help: local technicians
+ user training
Ministry of Interior
PEA
Installation company
End users
$
$
SHS
Missing linkages
warranty
Tax payers
$
Feedback on status of systems, failure
modes, successful interventions
Figure 3: Thailand’s solar home system program is characterized by key missing linkages (shown as red dotted arrows). Training is needed for local technicians and users on maintenance and simple repairs. End users lack information on warranty rights and claims procedures. There are also no institutionalized feedback systems from end users to the PEA, or Ministry of Interior, or the Thai public so that lessons learned from the Thai program can be internalized and mistakes avoided in subsequent similar programs.
A (limited) grassroots response: The Border Green Energy TeamWhile many NGO rural development groups work in many rural areas that
have been recipients of solar home systems, very few groups have technical skills to work on solar home systems. It appears, so far, that only one systematic grass-roots initiative has arisen to address issues related to solar home system sustainability. The Border Green Energy Team (BGET)11 is a joint project of Taipei Overseas Peace Service (TOPS), Palang Thai, Green Empowerment, and Karen Network for Culture and Environment (KNCE). BGET works to promote renewable energy in the Thailand-Burma border region. BGET’s website is: www.bget.org. In addition to BGET, a group connected with the KNCE’s Chiang Mai office has begun work on solar home system maintenance issues in Chiang Mai province.
So far, BGET’s solar home system activities have focused on only two districts (Amphurs) in Tak province. BGET works with local subdistrict (awbawtaw) governments to provide 2½ day trainings on system maintenance, operation, and repair. The participants are selected by the local government such that each village
cluster (mooti) has at least two trainees. While the theory behind the system’s operations is discussed, the focus of the workshops is practical hands-on training. This training includes inspections of SHSs in the village in which the training takes place. The status of each system and solutions to problems that are found are discussed as a group. During the course of the training each student also inspects and surveys at least one system on his own under the watchful eye of a BGET engineer. The training culminates in a practical test in the form of a system diagnosis. All students who pass this examination are issued a certificate and a toolbox with all the tools necessary to perform surveys in their home villages (tool box includes a multimeter, protective goggles, a head lamp, wire stripper, pliers, a utility knife, screwdrivers, electrical tape, and miscellaneous installation materials). Illustrated Thai and English language manuals developed for the course are available at: http://www.palangthai.org/en/bget. The survey form used is available in the manual. An English version is included in Appendix B of this study.
When the newly-trained technicians return to their communities, they survey all SHS and then fill out BGET survey forms and send them to the awbawtaw offices which relay the forms to BGET. Warranty claim forms (see Appendix C), created and distributed by BGET, are filled out by the awbawtaw officials and sent to the PEA.
Surveying SHS StatusIn order to gather data on the status of the SHSs as well as to help facilitate
warranty claims by villagers, BGET devised and distributed a survey questionnaire form to be filled out by BGET-trained surveyors in their own communities. A copy of this survey form is attached in part C of the Appendix. The survey was implemented in Tak Province. In Tak, all solar home systems were installed by the company Solartron, Ltd.
The questionnaire form starts with details of the location and ownership of the system, including the owner’s name, house number, and province, district (Amphur), subdistrict (tambon), village group (mooti or moo), and village. Also included are the surveyor’s name and the survey date.
Next in the survey is a section in which the electric load of the household is catalogued (in Watt-Hours). Following this, various voltage measurements are recorded from the solar panel, battery, and charge controller/inverter. From these measurements the status (good or bad) of each of these components of the system are determined and recorded on the form. The light/ballast units are also evaluated.
The next part of the survey investigates the owner’s experience with the system. The homeowner is asked to describe any problems the system has had, how long it has been broken, what kinds of benefits it provides, and if and how the owner has been maintaining the system. The last part of the form asks the homeowner how much he or she could afford to pay per month for the ongoing sustainability of the system with emphasis on the replacement of broken components. This question will be used to help gauge whether the average household can be SHS sustainable without government aid.
The homeowners, due to the nature of the SHS’ application, are rural villagers and most of them support themselves agriculturally. They are predominately very poor. In addition to ethnically Thai villagers, many of the SHS users in Tak province are ethnically Karen Thai citizens.
As discussed above, the surveyors who fill out these questionnaire forms are local technicians, Tambon government employees, and villagers who have taken part
in one of BGET’s Solar Home System Training workshops in cooperation with the local Tambon government offices
Analysis of Survey ResultsAfter BGET training, participants perform the SHS survey in their moo
(village group). The surveys take place in the following month and the completed survey booklets are submitted to awbawtaw offices and later BGET will collect them.
The total of 405 surveys for this report were gathered from two Amphurs (40% from Tha Song Yang and 60% from Mae Ramat) in Tak Province. The surveys were performed between December, 2005 and March, 2006 by ten different surveyors.
In some cases, the broken systems can not only be detected by voltage measurement alone but also by surveyor observation. To measure the correct battery voltage, the battery needs to be disconnected from the system for 30 minutes but in the actual survey this is not feasible. This leads to a higher voltage measurement than the actual one. Also for the charge controller/inverter unit and ballast/light bulb, the surveyor might need the user’s inputs to determine if the components do not work as they should. Thus, the information provided by the system users (obtained from survey question number 24, Appendix B) is essential. The failure rates are tabulated into individual broken component by the voltage measurement and by both voltage measurement and surveyor observation in Table 1. The major failure modes are charge controller/inverter unit (10.1%) and ballast/lamp unit (9.6%). The overall system failure is 22.5%.
Table 1: Individual component failure rates and overall system failure rate. The overall rate is lower than the sum of component failures because some systems had more than one broken component – for example a system with a broken charge controller/inverter and a broken ballast is still “one” system failure.
The typical loads and usage hours are illustrated in Table 2. Each solar home system initially includes two 10 watt fluorescent lights. The systems are primarily used for lighting and entertainment. The lights facilitate cooking, studying, gathering, and working including sewing and weaving. Entertainment includes watching TV or VCD and listening to radio.
Typical Load No. of system Typical Usage hours per day10 watt fluorescent light 405 3 - 4other light bulbs (7 to 20 watt) 20 3 - 4
Television rated from 20 to 100 watt 68 1 VCD player 2 N/A
Table 2: Typical loads and usage hours.
Some users maintain the systems by cleaning solar panels and filling batteries with distilled water, but most users do not do regular maintenance.
Sources of SHS FailureAfter less than 2 years approximately 22.5 percent of the SHSs surveyed have
failed. These failures can be classified into manufacturing defects, installation errors, and user errors.
Manufacturing defectsAccording to survey results from two Ampurs in Tak province, the most
common defective is the charge controller/inverter unit12 (failing in 10.1% of systems surveyed). About half the time the charge-control function of the unit fails, but the inverter continues to work. The failure mode is typically “open circuit” so that the battery no longer receives current from the solar PV module. In many cases, users “solve” the problem by bypassing the charge-control function by connecting the module directly to the battery. This can lead to subsequent failures, as described in the “user errors” section.
In other cases, the inverter function fails, so that the solar electric systems stop producing 50 Hz, 220 volt AC electricity. In this case, users sometimes hook up 12-volt loads to continue benefiting from electricity produced by the PV module and stored in the battery.
The inverter/charge control failures described above sometimes happen for no particular reason, according to survey respondents. Other times, inverter failures are triggered by short circuits in AC appliances or short-circuit failures of the fluorescent light ballast. While many international inverters are effective in short-circuit or overload self-protection, the inverters installed in the SHS program in Tak province are apparently not 100% reliable in self-protection.
Figure 4: An inverter/charger failure.
12 Manufactured by Forth Corporation public co.ltd: www.forth.co.th
Usually only one LED is lit at any one time, indicating battery level: green-full, yellow-medium, and red-empty. This failed inverter
has all 3 lights lit.
The second most common piece of equipment to fail is the lighting ballast, occurring in 9.6% of systems surveyed. When the ballast fails, the light fails to turn on. Sometimes ballast fails in a “short-circuit” fashion, triggering inverter shutdown and (in some cases) inverter failure.
Figure 5: 12 volt ballast
The BGET survey has also encountered battery failures in 5.9% of the systems surveyed. The most common manufacturing defect is in the form of weak cell assembly. The faulty cell will noticeably consume more water than the other cells do. This leads to less hours of electricity usage.
Solar modules also suffer from manufacturing defects, but this failure mode (0.7% of all system failures) is rare compared to the failure modes discussed above. Most common are missing electrical connectors in the junction box and the installation of diodes with wrong polarity. These manufacturing defects are shown below. Both of these defects ensure that the systems pictured never worked from the first day of installation. If the system installers had simply checked the status of the system before leaving, both problems could have been easily solved. BGET can fix these problems in the field with no need to file a warranty claim.
Figure 6: Solar module manufacturing defect: missing connector in junction box
Correct
Missing
Figure 7: Solar module manufacturing defect: incorrect diode polarity in junction box.
Installation errorsIn general, installations are of high quality: wires are fastened securely to the
walls, and connections are generally good. However, in some cases we have observed installation errors that have lead to system failure. Such errors include installation of solar panels in shade and mounting the charge controller/inverter unit in areas vulnerable to water damage from rain or dripping water. Solar panel shading leads to incomplete charging and often to over-discharge of the battery and sulfation of the battery plates. This leads to premature battery failure.
Figure 8: shaded solar panel location
Correct polarity Incorrect polarity
Figure 9: Another poor installation site
User errorIn addition to manufacturing defects and installation error, user errors are
fairly common. When the charge controller/inverter unit fails, owners frequently bypass the charge controller and charge the battery directly from the solar panels. This user error is another major source of further system damage and failure. Bypassing the charge controller generally leads to battery over-charge and excessive electrolyte loss, leading to the exposure of the battery plates and battery failure. Charge controller bypass can also lead to the explosion of the bypass diode in the solar panel junction box when a battery to be charged is mistakenly attached in reverse polarity.13 The resulting junction box explosion/fire/melting frequently renders the solar PV panel useless. Another common user error is placing excessive loads (too many, or too large appliances) on the SHS. This causes the battery to be discharged more often and more completely, shortening battery life. Occasionally, users will try to parallel the ac output of two inverters, which destroys both inverters.
13 The same issue still plagues Thailand’s solar battery charging stations. See: The Role of Bypass Diodes in the Failure of Solar Battery Charging Stations in Thailand. Solar Energy Materials and Solar Cells. Elsevier Press. Vol. 70. pp. 141-149. 2001. Chris Greacen and Donna Green. http://www.palangthai.org/docs/BipassDiodes.pdf
Figure 10: Bypassed broken charge controller/inverter. This leads to system failures in two key ways: (1) battery overcharge; and (2) burned/exploded diodes in PV module junction box because of reverse polarity connection to battery.
Figure 11: battery sulfation from chronic undercharge (module shaded). The un-even sulfation suggests a possible battery manufacturing defect as well.
healthy, without sulfation
sulfated plates
connected to battery plus and minus
connected to solar panel plus
and minus
Figure 12: melted junction box with exploded/burned diode after one reverse polarity mistake by villager during battery charging. Systems would be better if all bypass diodes were removed.
Figure 13: User error. Villager using an inefficient 60 W incandescent light bulb, placing unnecessary extra load on the system. Incandescent lights are tempting because they are cheaper than fluorescent lights, and villagers have little way of knowing that they consume much more power.
User ability to pay – and the unresolved issue of system stability after the warranty period expiresThe last question in the survey asks about how much villagers can pay for per month. Of 154 respondents to this question, 52 said they could pay 10 baht, 100 reported they could pay pay 20 baht, and 2 people can pay 30 baht. None reported higher monthly amounts than this.
In contrast, taking into consideration the expected lifetime and costs of different components, the estimated monthly cost of equipment depreciation is 130 baht to 300 baht per month (Figure 14).
Figure 14: Estimated total equipment replacement costs (with equivalent monthly payments) over 25 year period based on expected equipment lifetimes and costs.
The observed gap between the villagers’ willingness to pay and the longterm replacement costs suggests a looming sustainability problem after the warranty period expires. We suggest that unless some funded program effectively addresses ongoing local operations and repair needs, the useful lifetime of the solar home systems in Thailand will fall short of the bright potential inherent in this clean, decentralized technology.
Appendix A: Population Density and SHS Distribution Maps
Population density data and map from the Thai Government’s “Population and Housing Census 2000” (http://web.nso.go.th/pop2000/pop_e2000.htm)
PEA region designations and map directly from the PEA (http://www.pea.co.th/eweb/s_servicearea.htm)
